I really loved this book.  It is about a royal family who live in a magical castle. This castle is constantly changing based on what it feels is needed.  If it likes you,  your room might grow and get very nice but if it doesn’t like you, get ready for an uncomfortable stay.  This castle even picks who will be king.  When the King and Queen go missing while picking up the eldest son from Wizardry school, a neighboring Prince wants to take over the castle.  Cecilia and her brother Rolf are left to figure things out as the Castle gives them clues. This is the first book of three in this series.